There are certain moments in US history when Confederate monuments go up

By Saeed Ahmed, CNNDesign: Ryan Struyk and Sean O'Key, CNN

Updated 4:05 PM ET, Wed August 16, 2017

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(CNN)To hear their defenders say it, Confederate memorials aren't symbols of hate; they are meant to honor a heritage.

But, as this chart above from the Southern Poverty Law Center shows, whenever the country appeared to have made some racial progress, cities and states -- mostly in the South -- responded by erecting such monuments.

There are two distinct spikes: one around the turn of the 20th century, and one during the height of the civil rights movement.

The first spike

The first spike is around 1900. That's 35 years after the end of the Civil War.

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When the war ended, relatively few monuments went up in the South. The economy and social order were just too devastated. But after money was raised, sponsoring groups promoted the "Lost Cause" ideology -- the belief that states' rights, not slavery, was the Confederacy's principal cause.

By 1900, many states were implementing Jim Crow laws, meant to disenfranchise newly freed African-Americans and prevent integration.

It's in this climate that cities and states ramped up their construction of Confederate symbols.

The second spike

The second, albeit smaller, spike is in the mid-1950s and 1960s. Change was in the air. Brown v. Board of Education. The Civil Rights Act. The Voting Rights Act. As the SPLC put it in its report, "The civil rights movement led to a backlash among segregationists."

That brings us to today

According to the SPLC, an Alabama-based nonprofit organization that monitors civil rights and hate speech across the country,there are:

At least 1,503 publicly sponsored Confederate symbols around the nation

These include 700 monuments and statues in public property. Most are in the South

10 major US military bases named after Confederate military leaders

9 official Confederate holidays or observances in six Southern states

There are the 10 states with the most spaces dedicated to the Confederacy: